Due to changes in government regulations in Australia and elsewhere, past methods of preventing termite attack or entry in buildings which have involved the use of pesticides under the slab and around the outside periphery of a building are now no longer possible to employ because of the detrimental effects of the residual chemical poisons. While new chemicals have been introduced to overcome this problem, such chemicals prove considerably more expensive to use. As a result, a number of different methods have been proposed or are now used with the aim of combating termite infestation or migration.
One such method involves the use of a product known as TERMIMESH which comprises a mesh of stainless steel which has pores of sufficiently small size to prevent the passage of termites therethrough. While such a material is effective, it is required to be "parged" at one edge to secure it in position. This is difficult to accomplish in certain positions and furthermore a number of inspections must be undertaken to ensure that the mesh is effectively secured in position by the parge and/or to ensure that no damage has been caused to the mesh. In addition, the use of this product tends to be particularly expensive.
Japanese patent literature, such as 316502/92, 88836/90, 250308/88, 99301/87, 346047/93 and 18822/84 describe methods of termite control which are particularly suited to the elevated timber structures mostly utilised in Japanese dwelling construction, chosen for its earthquake resistant properties. In such above ground structures, entry points for termites are not concealed and thus can be treated after construction and accessed during the life of the structure. However the Japanese patents are aimed at the provisions of alternate poisons which are less harmful and to methods for their use.
Japanese patent application No. 80008/92 describes methods of spraying treatment to areas about buildings where termites may breed in order to prevent such breeding. It describes the use of polyurethane resins to carry and encapsulate poisons whereby the effect of the poison is maintained for extended periods, unlike earlier methods where the termiticides used are dissolved by the resins such that their effectiveness is reduced or lost. The polyurethane resin mixtures formed are also useful as moisture barriers which can be applied to the ground under slabs to provide the dual purpose of moisture proofing and provision of a long term poison.
It is considered that the use of any poison is disadvantageous and the need to deposit sufficient mixture to cover the ground under a concrete slab would be very costly in terms of the volume of chemical required.
The present invention aims to overcome or alleviate at least one of the above disadvantages by providing improved methods of and means for preventing or minimising the passage or migration of termites or other insects into a building. The present invention, in a further aspect aims to provide methods and means which may be applied to protect building products and components from termites or other insects. Other objects and advantages of the invention will become apparent from the following description.